1. Field of Disclosure
The disclosure generally relates to power acquisition for spacecraft and, more particularly, to power acquisition using a single-axis slit sun sensor.
2. Prior Art
Prior art spacecraft typically acquire the sun for power safety using sun sensor assemblies, for example, either wide field of view (WFOV) sun sensor, narrow field of view (NFOV) slit sun sensor, or multi-axis slit sun sensors. The use of a wide field of view sun sensor for sun acquisition requires a clear diamond field of view (FOV) about 120×120 degrees wide. As the size of certain components of the spacecraft, such as the antenna, the radiator and the solar wing with concentrator, is increased, it has become difficult for spacecraft to find such large clear FOV. In addition, the use of a wide field of view sun sensor for sun acquisition can involve angular measurement processing requiring expensive electronic hardware, such as buffer channel hardware and hardware for angular measurement processing. Furthermore, for prior art power acquisition methods using NFOV slit sun sensors or multi-axis slit sun sensors, at least two slit sun sensors, typically orthogonal to each other, are needed to sweep a wide area of the sky to find the sun.
There is a need for a simpler, more robust method for power acquisition for reaching power safety in spacecraft. There is also a need for a spacecraft power acquisition method that avoids the use of expensive hardware used by WFOV sun sensor acquisition and is less complicated than previous NFOV sun acquisition.